Generally, light-sensitive materials that have been exposed to light are then subjected to processing that comprises color developing, desilvering, and rinsing and stabilizing.
Today, processing of light-sensitive materials is normally performed by photo processing shops. In such shops, processing is conducted continuously by means of automatic developing machines. To satisfy users' increasing demands for more prompt service, these photo processing shops have to complete processing and return films to their customers within a half day; that is, if they receive an order in the morning, they have to hand over a processed film in the evening of the same day. Lately, these shops are often requested to finish the work within only a couple of hours after the receipt of an order. Under such circumstances, the need of a more improved technique for rapid processing is pressing.
Meanwhile, Eastman Kodak has proposed Process RA-1, a novel method of processing color paper. It comprises three steps; 45-sec color developing, 45-sec bleach/fixing and 90-sec stabilizing. According to Process RA-1, the total processing time is three minutes, and the processing temperature is 35.degree. C.
Conventional methods for rapid processing can be divided into the following three categories:
(1) making improvements on light-sensitive materials so that they can be more suited to rapid processing;
(2) making improvements on instruments and means employed for processing; and
(3) making improvements on the compositions of processing liquids
Methods relating to (1) above include:
1. improving silver halide composition, such as reducing the sizes of silver halide grains [see Japanese Patent Open to Putlic Inspection (hereinafter abbreviated as Japanese Patent O.P.I. Publication) No. 77223/1976)] or reducing the amount of silver bromide;
2. using additives, such as adding 1-aryl-3-pyrazolidone with a specific structure to a light-sensitive material (see Japanese Patent O.P.I. Publication No. 64339/1981) or adding 1-arylpyrazolidone to a light-sensitive material (Japanese Patent O.P.I. Publication Nos. 144547/1982, 50534/1983, 0535/1983 and 50536/1983):
3. using quick-reacting couplers, such as a quick-reacting yellow coupler (see Japanese Patent Examined Publication No. 10783/1976, Japanese Patent O.P.I. Publication Nos. 123342/1975 and 102636/1976); and
4. reducing the thicknesses of photographic layers (see Japanese Patent Application Specification No. 204992/1985)
As for (2), Japanese Patent Application Specification No. 23334/1986 discloses an improved method of stirring processing liquids.
Methods belonging to the category (3) include:
1. using development accelerators;
2. increasing the concentration of a developing agent in a developer; and
3. decreasing the concentration of halide ions, in particular, that of bromide ions
Among various conventional methods for rapid processing, including those mentioned above, especially effective is the use of a light-sensitive material with a higher silver chloride content (see Japanese Patent O.P.I. Publication Nos. 95345/1983, 19140/1985 and 95736/1983). Such light-sensitive materials have recently put on the market (e.g. Ektacolor paper 2001 by Eastman Kodak Company, Konicacolor QA paper by Konica Co.).
Meanwhile, in recent years, to reduce processing costs as well as to prevent environmental pollution, desilvering has come to be conducted by using a bleacher and a fixer separately. This tendency is more pronounced in large-scale processing laboratories which have to reduce production costs and are under strict restrictions for pollution control. The use of a bleacher, however, involves various problems.
It is generally known that, if a low-silver light-sensitive material having a reflective support, such as color negative paper (hereinafter referred to as color paper), is treated in a bleacher immediately after color development, stains are formed on the surface of the light-sensitive material since a color developing agent that has been soaked into the light-sensitive material is oxidized due to the strong oxidative power of the bleacher. To avoid this problem, color paper, after color developing and before bleaching, is normally subjected to stopping and rinsing to wash away color developer components therefrom. This method is also defective, since it needs the provision of at least two processing liquid tanks between a color developer tank and a bleacher tank, which eventually results in an increase in cost. Under such circumstances, there is a strong demand for a method of processing color paper which can effectively prevent the formation of stains even when the color paper is treated in a bleacher immediately after color development.
Another serious problem is that, when color paper is treated in a bleacher, silver chlorobromide that is normally contained in color paper is reacted with a halide contained in a bleacher (e.g. ammonium bromide) to form silver-halogen complexes, which complexes are dissolved in the bleacher, while being diluted partially with a color developer brought into the bleacher tank by the color paper, and then precipitates in the bleacher tank to form sludge. The sludge causes clogging of a filter and other parts of an automatic processing machine, and makes it unable to work. This trouble occurs more frequently when only a small amount of a replenisher is used for a bleacher.
Still another problem accompanying the use of a bleacher is the harmful effect of a bleacher to work environments. For use, a bleacher has to be made acidic to maintain its high oxidation potential, and acetic acid is commonly used as a pH controller. Acetic acid tends to vaporize and diffuse with an offensive odor, affecting adversely the health of people working in processing laboratories.